1. Field of the Invention
The present invention relates to a supporting structure for a vibrator and, more particularly, to a supporting structure for a vibrator having a bending vibration mode which is used for a vibratory gyroscope or the like.
2. Description of the Prior Art
FIG. 5 is a side illustrative view showing an example of a conventional vibratory gyroscope which is a background of the present invention, FIG. 6 is a front illustrative view thereof, and FIG. 7 is a bottom view showing an essential portion thereof. The vibratory gyroscope 1 comprises a triangular prism-shaped vibrator 2, and two supporting members 3a and 3b made of wire rods are respectively secured to the vicinity of nodal points of the vibrator 2.
Both ends of one supporting member 3a are fixed to one mounting board 4a by soldering. In this case, in the mounting board 4a, two through-holes 5a are formed so as to leave a distance similar to a distance between both ends of the supporting member 3a. On almost the whole bottom face of the mounting board 4a, a ground conductor pattern 6a of copper foil for shielding is formed. On the mounting board 4a, connecting conductor patterns 7a are respectively formed on surfaces of portions defined by the through-holes 5a and surfaces of portions surrounded the through-holes 5a, so as to extend from the ground conductor pattern 6a. Both ends of the supporting member 3a are respectively inserted into the through-holes 5a of the mounting board 4a and soldered to the connecting conductor patterns 7a.
Similarly, both ends of the other supporting member 3b are respectively inserted into through-holes 5b of the other mounting board 4b having the same structure as one mounting board 4a, and soldered to connecting conductor patterns 7b extending from a ground conductor pattern 6b for shielding.
In addition, these mounting boards 4a and 4b are respectively bonded to a supporting base (not shown) such as a work plate via a cushioning material (not shown).
In the vibratory gyroscope 1 shown in FIGS. 5-7, though two supporting members 3a and 3b bend in opposite directions simultaneously with the vibration of the vibrator 2, these supporting members 3a and 3b scarcely interfere with each other, since these supporting members 3a and 3b are bonded to the supporting base via the cushioning material. Therefore, the vibration of the vibrator 2 is little suppressed by the supporting members 3a and 3b, and maintaining stable vibration of the vibrator 2 can be expected.
However, in the conventional supporting structure for the vibrator, when both ends of the supporting member are soldered to the connecting conductor patterns on the mounting board, an amount of heat which is released to the ground conductor pattern is large, and thus it sometimes occurs that solder cools at midway points of the through-holes in the mounting board to solidify and does not fill up the through-holes. If solder is not filled up in the through-holes of the mounting board, it becomes impossible to fix the supporting member to the mounting board with sufficient strength. Furthermore, if amounts of solder filling in the through-holes of the mounting board vary at every holes, this causes variations in vibrator characteristics.